今天仔细研究了一下差分法求运动的轮廓，简单用程序实现了一下，结果如下，
差分法比较容易获得运动的轮廓，对于不运动的身体部分则不会显示，
这样的好处是可以得到需要关注的运动部分，不运动的则不关心，
但是如果需要得到整个人体的轮廓，该如何呢？
我试着用程序记录前4帧的数据，然后叠加出来显示，看来效果不是很好。 还要继续考虑...

关键部分的代码如下：
main.cpp

#ifdef _CH_
#pragma package <opencv>
#endif

#ifndef _EiC
// motion templates sample code
#include "cv.h"
#include "highgui.h"
#include <time.h>
#include <math.h>
#include <ctype.h>
#include <stdio.h>
#endif

// various tracking parameters (in seconds)
const double MHI_DURATION = 1;
const double MAX_TIME_DELTA = 0.5;
const double MIN_TIME_DELTA = 0.05;
// number of cyclic frame buffer used for motion detection
// (should, probably, depend on FPS)
const int N = 4;

// ring image buffer
IplImage **buf = 0;
int last = 0;

// temporary images
IplImage *mhi = 0; // MHI
IplImage *orient = 0; // orientation
IplImage *mask = 0; // valid orientation mask
IplImage *segmask = 0; // motion segmentation map
CvMemStorage* storage = 0; // temporary storage

IplImage* abs_image = 0;
IplImage* add_abs_image = 0;
IplImage* abs_images[3];

IplImage* grey =0;
IplImage* pre_grey = 0;
IplImage* dst = 0;
  CvSeq* contour = 0;

int test( IplImage* src,IplImage* pre_src );

int main(int argc, char** argv)
{
    //IplImage* motion = 0;
    CvCapture* capture = 0;
 IplImage* pre_image = 0;
 IplImage* image = 0;
 int frame_count =0;

    if( argc == 1 || (argc == 2 && strlen(argv[1]) == 1 && isdigit(argv[1][0])))
        //capture = cvCaptureFromCAM( argc == 2 ? argv[1][0] - '0' : 0 );
  capture = cvCaptureFromFile("e:\\abc.avi");
    else if( argc == 2 )
        capture = cvCaptureFromAVI( argv[1] );
 
    if( capture )
    {
       
        //cvNamedWindow( "Motion", 1 );
  cvNamedWindow( "Source", 1 );
        cvNamedWindow( "Components", 1 );
       
        for(;;)
        {
           
            if( !cvGrabFrame( capture ))
                break;
            image = cvRetrieveFrame( capture );

   if (!pre_image)
   {
    pre_image = cvCreateImage( cvGetSize(image), 8, 3 );       
    abs_image = cvCreateImage( cvGetSize(image), 8, 1 );
    add_abs_image = cvCreateImage( cvGetSize(image), 8, 1 );
    
    grey = cvCreateImage( cvGetSize(image), 8, 1 );
    pre_grey = cvCreateImage( cvGetSize(image), 8, 1 );

    dst = cvCreateImage( cvGetSize(image), 8, 3 );
    abs_image->origin = image->origin;
    add_abs_image->origin = image->origin;
    dst->origin = image->origin;
    storage = cvCreateMemStorage(0);

    abs_images[0] = cvCreateImage( cvGetSize(image), 8, 1 );
    abs_images[1] = cvCreateImage( cvGetSize(image), 8, 1 );
    abs_images[2] = cvCreateImage( cvGetSize(image), 8, 1 );
    abs_images[3] = cvCreateImage( cvGetSize(image), 8, 1 );
    cvZero(abs_images[0]);

    cvZero(abs_images[1]);

    cvZero(abs_images[2]);

    cvZero(abs_images[3]);

   }

   frame_count++;
   test(image,pre_image);
   cvCopy(abs_images[frame_count%3],abs_image,0);
   cvCopy(image,pre_image,0);
            if( cvWaitKey(10) >= 0 )
                break;
        }
        cvReleaseCapture( &capture );
        //cvDestroyWindow( "Motion" );
    }

    return 0;
}
                               

int test( IplImage* src,IplImage* pre_src )
{
   
     

  cvCvtColor(src, grey, CV_BGR2GRAY);
  cvZero(add_abs_image);
  cvCvtColor(pre_src, pre_grey, CV_BGR2GRAY);
 
  cvAbsDiff( grey,pre_grey, abs_image );

        cvThreshold( abs_image, abs_image, 20, 255, CV_THRESH_BINARY );

  cvAdd(abs_images[0],abs_image,add_abs_image);
  cvThreshold( add_abs_image, add_abs_image, 10, 255, CV_THRESH_BINARY );
  
  cvAdd(abs_images[1],add_abs_image,add_abs_image);
  cvThreshold( add_abs_image, add_abs_image, 10, 255, CV_THRESH_BINARY );

  cvAdd(abs_images[2],add_abs_image,add_abs_image);
  cvThreshold( add_abs_image, add_abs_image, 10, 255, CV_THRESH_BINARY );
  cvAdd(abs_images[3],add_abs_image,add_abs_image);
  cvThreshold( add_abs_image, add_abs_image, 10, 255, CV_THRESH_BINARY );
 
//cvWaitKey(0);

        cvFindContours( abs_image, storage, &contour, sizeof(CvContour), CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE );
        cvZero( dst );

        for( ; contour != 0; contour = contour->h_next )
        {
            CvScalar color = CV_RGB( 255, 255, 255 );
            /* replace CV_FILLED with 1 to see the outlines */
   
  
            cvDrawContours( dst, contour, color, color, -1, CV_FILLED, 8 );
        }

  
        //cvNamedWindow( "Source", 1 );
        cvShowImage( "Source", src );
        //cvNamedWindow( "Components", 1 );
        cvShowImage( "Components", dst );
        //cvWaitKey(0);
  return 0;

}

#ifdef _EiC
main(1,"motempl.c");
#endif